The present invention relates to an optical device module in which a light emitting device which emits light from its surface substantially at right angles thereto, such as a laser diode, or a light receiving device which receives light substantially at right angles to its surface, such as a photo diode (which elements will hereinafter be generically referred to as an optical semiconductor device) and the optical path of an optical waveguide member such as an optical fiber or optical waveguide board, i.e. the core of the optical fiber or the optical waveguide of the optical waveguide board, are interconnected by an optical path bent substantially at right angles.
FIG. 9 is a diagrammatic showing of a conventional optical device module of this kind proposed in Japanese Patent Application Laid-Open Gazette No. 08-21930. Reference numeral 12 denotes a photo detector disposed in a casing 11, 13 a window made in the top panel of the casing 11, 14 a condenser lens fitted in the window 13, 15 an optical fiber disposed on the top of the casing 11, and 16 a reflecting surface formed by cutting one end face of the optical fiber 15 at an angle of about 45 degrees. Light propagated through the optical fiber 15 is bent at right angles by the reflecting surface 16 and gathered by the condenser lens 14 for incidence on the photo detector 12 as indicated by the broken line. In FIG. 3 of the above-mentioned official gazette there is also proposed such a construction as depicted in FIG. 10 in which the end face of the optical fiber 15 is perpendicular to its axis and the end face abutted against a prism 17 so that the light from the optical fiber 15 is bent at right angles by the prism 17 as indicated by the broken line.
In Japanese Patent Application Laid-Open Gazette No. 10-160959 there is proposed a conventional optical device module of this kind. As depicted in FIGS. 11 and 12, a frame-like guide block 21 with a rectangular opening has formed integrally therewith a guide prism 22, an optical fiber is disposed in each recess 23 of the guide block 21 with the end face of the optical fiber 15 abutted against the guide prism 22, and a light receiving device 24 is fitted in the frame of the guide block 21. Light from the optical fiber 15 is bent by the guide prism 22 for incidence on the light receiving device 24.
However, the prior art example of FIG. 9 suffers much difficulty in aligning the point of incidence on the reflecting surface 16 of the optical fiber 15, the axis of the lens 13 and the light-receiving center of the photo detector 12; hence, it is not easy to launch the light from the optical fiber 15 into the photo detector 12 with high efficiency. In the example of FIG. 10, too, it is very difficult to align the reflecting-point of the prism 17, the axis of the lens and the light-receiving center of the photo detector.
In the example of FIGS. 11 and 12, the abutment of the end face of the optical fiber 15 against one side of the guide prism 22 ensures accurate positioning, but the light receiving device 24 needs to be fitted snugly in the frame of the guide block 21. To meet this requirement, it is necessary that the inside dimensions of the frame of the guide block 21 and/or outside dimensions of the light receiving device 24 be adjusted for each optical device module. Hence, the illustrated structure lacks general versatility. Moreover, the light receiving device 24, once fitted in the frame of the guide block 21, is fixed and its position cannot be adjusted so that its light receiving surface is placed at a correct position.
It is therefore an object of the present invention to provide an optical device module free from the above-mentioned defects of the prior art.
According to the present invention, there is provided an optical device module comprising:
an optical waveguide member having at least one optical path, the optical waveguide member having a light emitting or receiving surface substantially at right angles to the longitudinal direction of the at least one optical path;
a transparent structure having a first side which supports one end portion of the optical waveguide member and a second side opposite the first side;
an optical semiconductor device disposed opposite said second side of the transparent structure and having a light emitting or receiving surface substantially at right angles to the second side of the transparent structure;
a plurality of positioning marks placed in the second side of the transparent structure for positioning the optical semiconductor device and the transparent structure relative to each other in a plane parallel with the second side of the transparent structure;
optical semiconductor device support means for supporting the optical semiconductor device on the second side of the transparent structure; and
a prismatic protrusion formed integrally with the transparent structure on the first side thereof;
wherein the prismatic protrusion has a positioning surface which extends substantially at right angles to the first side of said transparent structure for abutment with one end face of the optical waveguide member to position the optical waveguide member and a reflecting surface which crosses an extension of the at least one optical path of the optical waveguie member abutted against the positioning surface and slopes with respect to the first side of the transparent structure to form between the end face of the optical path and the optical semiconductor device a bent optical route passing through the transparent structure.